1986 Corvette Motor misses sometimes

[Bill]

I put new plug wires on. Checked the plugs(they are good)
I put in injecter cleaner. That seemed to help.
It will miss from time to time. Never know when it will do it.
It is noticeable when you pull up to a stop sign. It isn't smooth.
The motor was rebuilt and has about 20,000 on re-build.
Any advise will help. I don't drive it that often, couple times a month.
Thanks

 

[JT ZR-Won]

Have you replaced the fuel filter lately? Also, how are your plug wires? If they are old, the slightest crack in the wire will make the car run a little rough.
I would also check to see if all the the terminals on the cap & rotor are not corroded......

Jay

 

[hoosierguy60]

gas octane

i have an 86 also and it seems like if i use 87 octane the car misses out more i also agree plugs look good but can be brokedown internally, along with the cap , dont get the cheap aluminum point one , get the copper tipped one ...doesnt corrode as easy...good luck

 

[vigman]

Missing

Lets see if I've got this...
New wires, checked plugs ( what kind of plugs are you running) OLD Cap & rotor? No error codes ( Check engine light?) It looks like cleaning the IAC is next.

Buy a new throttle body gasket before starting!!!!
and probably a new hose from the intake mainfold to the throttle body.

Remove throttle body (2 water hoses,2 electrical connectors, throttle & cruise linkage, 2 vac lines).
remove IAC VALVE

Clean carefully the cavity in the throttle body.
Clean the back side of the throttle body.
Check for play ( wiggle ) of the throttle plates & shaft.. if it moves there a good chance your leaking air around the plates, this needs to be fixed.My local carb shop re-bushed mine for $125.00

Clean the pintle ( TIP ) of the IAC valve DO NOT LET ANY CARB CLEANER RUN DOWN THE SHAFT OF THE IAC.

Re assemble.
It would be a good idea at this point to check the TPS ( Throttle position sensor ) for .54 volts at idle ( key on, engine off, volt meter DC across pins A&B with TPS connected.)

Start car and Immediatly & shut it off then start again... this will relearn the IAC settings.


Mike

 

[hoosier]

missing

Hey Mike would it also help to drain a little radiator fluid first , LOL

Barry